1. Field of the Invention
The present invention is directed to a controller for a complementary Regenerative Torque System (RTS) for a vehicle, the interface to the existing vehicle components, and the associated control thereof.
2. Description of the Related Art
Conventional vehicles have an internal combustion engine as a single source of torque. FIG. 1 depicts a schematic flow chart of the signal and torque flow and associated control of a conventional four wheel drive vehicle. An Accelerator Pedal Position (APP) sensor is often employed to indicate desired engine torque while an Engine Control Module (ECM) controls the engine in response to the APP and other sensed conditions. The ECM communicates with a Transmission Control Module (TCM) which controls the transmission in accordance with APP, engine output torque, engine speed and vehicle speed, amongst other conditions. Such assemblies are well known in the art. These prior art systems do not have the ability to provide complementary or supplemental torque, or the ability to store or otherwise use the tremendous amount of energy wasted during vehicle deceleration.
The prior art has presented a wide variety of vehicular systems designed to capture and store a portion of the kinetic energy lost to brake heating in a decelerating vehicle, and to use the stored energy to re-accelerate the vehicle. Such systems often convert the torque of a drive shaft somewhere between the transmission and the axle of the vehicle drive wheels. Some systems employ electric hybrid components consisting of electric motor generators, batteries, and capacitors to convert kinetic energy while braking to electrical potential energy for driving the motor when torque is needed. Other systems employ hydraulic hybrid components consisting of pumps, motors and accumulators to convert kinetic energy while braking to hydraulic potential energy for driving the motor when torque is needed.
An example of a hydraulic RTS employs an integrated Pump Motor (P/M) which is driven by the drive train of the vehicle. The P/M shifts between a generative pump mode to charge a hydraulic accumulator and a motor mode which supplies torque to the drive train. Such pump motors are well known to those of ordinary skill on the art. Many such designs include a variable displacement P/M with a swash plate. When the swash plate is at zero angle, the pistons of the P/M are not reciprocating with respect to the cylinder block and the P/M is neither pumping nor motoring. The position of the swash plate is controlled in response to the mode of operation of the RTS. When braking, the P/M becomes a pump which charges a pressure accumulator. When accelerating, the pressure accumulator powers the P/M which then acts as a motor supplying torque the drive train.
All such prior devices and systems are costly and difficult to be installed with control systems of existing vehicles and are not especially adapted for simple integration with an existing control system and fail to provide the benefits associated with the assembly according to the present invention.